Elasticsearch系统学习(三)-document基本操作
一、document数据格式
(1)应用系统的数据结构都是面向对象的,复杂的
(2)对象数据存储到数据库中,只能拆解开来,变为扁平的多张表,每次查询的时候还得还原回对象格式,相当麻烦
(3)ES是面向文档的,文档中存储的数据结构,与面向对象的数据结构是一样的,基于这种文档数据结构,es可以提供复杂的索引,全文检索,分析聚合等功能
(4)es的document用json数据格式来表达
{ "email": "zhangsan@sina.com", "first_name": "san", "last_name": "zhang", "info": { "bio": "curious and modest", "age": 30, "interests": [ "bike", "climb" ] }, "join_date": "2017/01/01" }
二、简单集群管理
2.1、快速检查集群的健康状况
es提供了一套api,叫做cat api,可以查看es中各种各样的数据,使用GET /_cat/health?v查看集群状态,?v添加表头
GET /_cat/health?v epoch timestamp cluster status node.total node.data shards pri relo init unassign pending_tasks max_task_wait_time active_shards_percent 1567342207 20:50:07 elasticsearch yellow 1 1 1 1 0 0 1 0 - 50.0%
集群的健康状态:
green:每个索引的primary shard和replica shard都是active状态的
yellow:每个索引的primary shard都是active状态的,但是部分replica shard不是active状态,处于不可用的状态
red:不是所有索引的primary shard都是active状态的,部分索引有数据丢失了
为什么现在会处于一个yellow状态?
我们现在就一个笔记本电脑,就启动了一个es进程,相当于就只有一个node。现在es中有一个index,就是kibana自己内置建立的index。由于默认的配置是给每个index分配5个primary shard和5个replica shard,而且primary shard和replica shard不能在同一台机器上(为了容错)。现在kibana自己建立的index是1个primary shard和1个replica shard。当前就一个node,所以只有1个primary shard被分配了和启动了,但是一个replica shard没有第二台机器去启动。
实验测试:
此时只要启动第二个es进程,就会在es集群中有2个node,然后那1个replica shard就会自动分配过去,然后cluster status就会变成green状态。
epoch timestamp cluster status node.total node.data shards pri relo init unassign pending_tasks max_task_wait_time active_shards_percent 1567342754 20:59:14 elasticsearch green 2 2 2 1 0 0 0 0 - 100.0%
2.2、快速查看集群中有哪些索引
GET /_cat/indices?v
GET _cat/indices?v health status index uuid pri rep docs.count docs.deleted store.size pri.store.size green open .kibana mtCLy37mTr-eW0g1ATAEFw 1 1 1 0 6.3kb 3.1kb
2.3、简单索引操作
1)创建索引:PUT /test_index?pretty
PUT /test_index?pretty { "acknowledged": true, "shards_acknowledged": true } GET /_cat/indices?v health status index uuid pri rep docs.count docs.deleted store.size pri.store.size green open .kibana mtCLy37mTr-eW0g1ATAEFw 1 1 1 0 6.3kb 3.1kb green open test_index cpTW7zzOQkKm9Mi7Omu2Sw 5 1 0 0 1.2kb 650b #新创建的索引
2)删除索引:DELETE /test_index?pretty
DELETE /test_index?pretty { "acknowledged": true } GET /_cat/indices?v health status index uuid pri rep docs.count docs.deleted store.size pri.store.size green open .kibana mtCLy37mTr-eW0g1ATAEFw 1 1 1 0 6.3kb 3.1kb
三、文档的CRUD操作
3.1、新增商品:新增文档,建立索引
格式:
PUT /index/type/id { "json数据" }
添加测试用文档:
PUT /ecommerce/product/1 { "name" : "gaolujie yagao", "desc" : "gaoxiao meibai", "price" : 30, "producer" : "gaolujie producer", "tags": [ "meibai", "fangzhu" ] } #返回 { "_index": "ecommerce", "_type": "product", "_id": "1", "_version": 1, "result": "created", "_shards": { "total": 2, "successful": 1, "failed": 0 }, "created": true } #在添加两条 PUT /ecommerce/product/2 { "name" : "jiajieshi yagao", "desc" : "youxiao fangzhu", "price" : 25, "producer" : "jiajieshi producer", "tags": [ "fangzhu" ] } PUT /ecommerce/product/3 { "name" : "zhonghua yagao", "desc" : "caoben zhiwu", "price" : 40, "producer" : "zhonghua producer", "tags": [ "qingxin" ] }
es会自动建立index和type,不需要提前创建,而且es默认会对document每个field都建立倒排索引,让其可以被搜索
3.2、查询商品,检索文档
格式:GET /index/type/id
GET /ecommerce/product/1 { "_index": "ecommerce", "_type": "product", "_id": "1", "_version": 1, "found": true, "_source": { "name": "gaolujie yagao", "desc": "gaoxiao meibai", "price": 30, "producer": "gaolujie producer", "tags": [ "meibai", "fangzhu" ] } }
3.3、修改商品:替换文档
替换方式有一个不好,必须带上所有的field,才能去进行信息的修改
GET /ecommerce/product/1 { "_index": "ecommerce", "_type": "product", "_id": "1", "_version": 1, "found": true, "_source": { "name": "gaolujie yagao", "desc": "gaoxiao meibai", "price": 30, "producer": "gaolujie producer", "tags": [ "meibai", "fangzhu" ] } } #替换 PUT /ecommerce/product/1 { "name" : "jiaqiangban gaolujie yagao", #名称改变 "desc" : "gaoxiao meibai", "price" : 30, "producer" : "gaolujie producer", "tags": [ "meibai", "fangzhu" ] } { "_index": "ecommerce", "_type": "product", "_id": "1", "_version": 2, "result": "updated", "_shards": { "total": 2, "successful": 2, "failed": 0 }, "created": false } #再次查看 { "_index": "ecommerce", "_type": "product", "_id": "1", "_version": 2, "found": true, "_source": { "name": "jiaqiangban gaolujie yagao", #更改了 "desc": "gaoxiao meibai", "price": 30, "producer": "gaolujie producer", "tags": [ "meibai", "fangzhu" ] } } #缺点:当使用如下替换时,只会剩下name PUT /ecommerce/product/1 { "name" : "jiaqiangban gaolujie yagao" }
3.4、修改商品:更新文档
格式:POST /index/type/id/_update
GET /ecommerce/product/1 { "_index": "ecommerce", "_type": "product", "_id": "1", "_version": 3, "found": true, "_source": { "name": "gaolujie yagao", "desc": "gaoxiao meibai", "price": 30, "producer": "gaolujie producer", "tags": [ "meibai", "fangzhu" ] } } POST /ecommerce/product/1/_update { "doc":{ "name": "jiaqiangban gaolujie yagao" } } { "_index": "ecommerce", "_type": "product", "_id": "1", "_version": 4, "result": "updated", "_shards": { "total": 2, "successful": 1, "failed": 0 } } get /ecommerce/product/1 { "_index": "ecommerce", "_type": "product", "_id": "1", "_version": 4, "found": true, "_source": { "name": "jiaqiangban gaolujie yagao", "desc": "gaoxiao meibai", "price": 30, "producer": "gaolujie producer", "tags": [ "meibai", "fangzhu" ] } }
3.5、删除商品:删除文档
格式:DELETE /index/type/id
delete /ecommerce/product/1 { "found": true, "_index": "ecommerce", "_type": "product", "_id": "1", "_version": 5, "result": "deleted", "_shards": { "total": 2, "successful": 1, "failed": 0 } } GET /ecommerce/product/1 { "_index": "ecommerce", "_type": "product", "_id": "1", "found": false }
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